Are P[A,B] Independent When P[A|B]=P[A|B^c]?

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SUMMARY

The discussion centers on proving the independence of events A and B given that P[A|B] = P[A|B^c]. The key equation derived is P(A ∩ B) / P(B) = P(A ∩ B^c) / P(B^c). The proof requires demonstrating that P(A ∩ B^c) / P(B^c) equals P(A), which can be achieved using the identity P(A ∩ B^c) = P(A) - P(A ∩ B). This approach clarifies the relationship between conditional probabilities and independence.

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Homework Statement


Given that [tex]P[A|B]=P[A|B^c][/tex], prove that they are independent.

The Attempt at a Solution



So we have that [tex]\frac{P(A\cap B)}{P(B)}=\frac{P(A\cap B^c)}{P(B^c)}[/tex]. I would have to show that [tex]\frac{P(A\cap B^c)}{P(B^c)}=P(A)[/tex]. I can't make that happen.
 
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Try using the fact that [tex] P(A \cap \overline B ) = P(A) - P(A \cap B)[/tex], i think.
 
Got it. This was unusually convoluted for something so trivial.
 

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